The present invention relates to timing devices and pertains particularly to a flowing medium type timing device.
Hour glasses and similar timing devices have been known for centuries. The conventional construction of an hour glass, however, limits its timing to a particular interval of time for each hour glass. Thus, any hour glass is designed to measure only a single duration of time and are not capable of selective intervals of time.
The time interval determined by an hour glass and similar such timing devices is determined by the quantity of the flowing medium and the restriction to flow as imposed by the structure of the timer. Thus, each hour glass is designed for a particular time interval.
It is desirable that flowing medium hour glass type timers be available which have selective durations of time.